Prototype nitinol heat engine. Final report

Technical Report · Sat Nov 01 04:00:00 EST 1980

OSTI ID:6642626

McNichols, Jr, J L; Brookes, P C; Ginell, W S; Cory, J S

The principal objective of the program was to demonstrate that Nitinol heat engines can be scaled to higher powers. The approach was to build a series/parallel Nitinol thermoturbine engine based upon the principle of, and scaled up in power from, small (less than or equal to 1 watt) single band thermoturbine engines which had previously been built and operated successfully. Equipment and instrumentation were built up for the measurements of the Nitinol helix force-length-temperature (FLT) behavior (state equation). Nitinol 20 mil diameter wire was wound in the form of 1 mm radius helical engine elements. The Nitinol elements were characterized and design equations, which relate engine performance to the Nitinol FLT properties and to machine dimensions, were used to perform engineering trade-offs to optimize performance and to specify engine component sizes, machine dimensions and heat source/sink requirements for optimal performance. A module engine was built with two series cycles and eighty parallel Nitinol helical bands. The module was instrumented so that performance could be monitored and diagnostic measurements could be made. The module operated successfully according to the design concept principles. The module was tested for sink temperatures from approx. 9/sup 0/C to 20/sup 0/C and with source temperatures from approx. 50/sup 0/C to approx. 75/sup 0/C. Torque, power and frequency were measured. The peak shaft power output obtained during the performance testing of the series/parallel thermoturbine was greater than 32 watts. This power is the largest yet reported for Nitinol heat engines, is more than 30 times greater than the small single band engines previously built, and clearly demonstrated the feasibility of scaling Nitinol heat engines to larger powers.

• Research Organization: McDonnell Douglas Astronautics Co., Huntington Beach, CA (USA)
• DOE Contract Number: AC05-78OR06028
• OSTI ID: 6642626
• Report Number(s): MDC-G-9290
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140700 -- Solar Thermal Power Systems
42 ENGINEERING
425007* -- Engineering-- Power Cycles-- Other-- (1980-)
ALLOYS
DESIGN
DIMENSIONS
ENERGY LOSSES
ENGINES
FABRICATION
FAILURES
FRICTION
HEAT ENGINES
LOSSES
MATHEMATICAL MODELS
NICKEL ALLOYS
NITINOL
NITINOL HEAT ENGINES
OPTIMIZATION
PERFORMANCE
PERFORMANCE TESTING
POWER LOSSES
POWER RANGE 10-100 W
SCALING LAWS
SIZE
TESTING
TITANIUM ALLOYS
TORQUE
WIRES